Researchers at the Chemical Engineering Laboratory of the Federal Institute of Technology in Zurich recently invented a thin, curved light-emitting diode (LED) that emits a very pure green light that the researchers used to show three-letter "ETH". Professor Chih-jen Shih, head of the research team, was very pleased with his breakthrough: "So far, no one has succeeded in producing pure green light like ours." ”

Prof Shih says the study will help the next generation of ultra-high-resolution displays for TVs and smartphones. The electronic device screen must be able to produce ultra pure red, blue, and green light so that the display can produce clearer, richer details and a finer range of colors to adjust the image.

Prior to the technical research has been able to achieve the purity of red and blue production, but the pure color green light seems to have encountered a technical bottleneck, it is difficult to achieve technological breakthroughs, mainly due to visual constraints. Compared to red and blue light, it is difficult for the naked eye to distinguish the changes in green tones, which makes the super pure green in the technical production becomes very complex.

Prof Shih also points out that they have developed a thin, flexible light-emitting diode that can be used to emit pure green light at room temperature. "Because our LED technology does not require high temperatures, it opens up opportunities for the simple, low-cost industrial production of future Ultra pure Green light-emitting diodes," he said. "The team used perovskite crystals as LED radiation light, and the thickness of the perovskite material in the LED was less than 4.8 nm," he said. And the LED material can be made like paper can be bent, so that it can be achieved in volume to the volume of rapid production process, not only improve production efficiency, but also reduce production costs.

But this ultra pure green LED will take some time before it is put into industrial use. Shih the next step is to improve the efficiency of the LED, the LED power conversion to the light aging rate of only 3%, the market on the television screen electro-optic conversion efficiency of 5% to 10%. He hopes to improve the efficiency of pure green LEDs to 6% to 7%. In addition, the LED's illuminating life is now about 2 hours, which is quite different from the screen on the market, and these are the areas where the Shih team needs to improve on the invention.